1. Field of the Invention
The present invention relates to ultrasonic temperature measurement and more particularly to a novel remote ultrasonic temperature sensor.
2. Description of the Prior Art
It is well known that the elastic modulus of a material is temperature dependent, that the temperature may be measured by measuring the velocity of propagation of acoustic waves in the material. The most common method of measurement is to use a transit time or time of flight measurement, in which reflections are produced at two different locations in a sensing element. Since the "time of flight" should be measured in material exposed to the same temperature, and since the electromechanical transducer cannot ordinarily be exposed to high temperatures, it is conventional to provide an acoustic coupling means between the transducer in a normal environment and the coupling element in the high temperature environment. Unfortunately, conventional solid rods used for acoustic coupling require supporting clamps, which interfere with the coupling function by generating unwanted reflections.